THE PERIODIC TABLE

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THE PERIODIC TABLE

Chapter 7

THE PERIODIC TABLE


Lesson 1

Using the Periodic Table


Lesson 2

Metals


Lesson 3

Nonmetals and Metalloids

LESSON 1: USING THE PERIODIC TABLE


Key Concepts


How are elements arranged on the periodic table?


What can you learn about elements from the periodic table?

LESSON 1: USING THE PERIODIC TABLE


What is the periodic table?


The
peri
odic table
is a chart of the elements
arranged into rows and columns according to their
physical and chemical properties.


It can be used to determine the relationships
among the elements.


LESSON 1: USING THE PERIODIC TABLE


Developing a periodic table


When Russian chemist
Dimitri

Mendeleev was
working on classifying the elements, he placed his
list of elements into a table and arranged them in
rows of increasing atomic mass.


Elements with similar properties were grouped in
the same column.


LESSON 1: USING THE PERIODIC TABLE


Mendeleev noticed that melting point is one
property that shows a repeating pattern.

LESSON 1: USING THE PERIODIC TABLE


Developing a periodic table (cont.)


Boiling point and reactivity also follow a periodic
pattern.


Mendeleev believed that the atomic masses of
certain elements must be invalid because the
elements appeared in the wrong place on the
periodic table.


He placed elements whose properties resembled
each other’s closer together in the table.

LESSON 1: USING THE PERIODIC TABLE


When Moseley listed the elements according to
atomic number, columns contained elements with
similar properties, such as copper, silver, and gold.

LESSON 1: USING THE PERIODIC TABLE


Today’s periodic table


You can identify many of the properties of an
element from its placement on the periodic table.

period

Science Use

the completion of a
cycle; a row on the periodic table

Common Use

a point used to mark
the end of a sentence; a time frame

LESSON 1: USING THE PERIODIC TABLE


The table is organized into columns, rows, and
blocks, which are based on certain patterns of
properties.

LESSON 1: USING THE PERIODIC TABLE


Today’s periodic table (cont.)


The element key shows an element’s chemical
symbol, atomic number, and atomic mass.


The key also contains a symbol that shows the
state of matter at room temperature.

LESSON 1: USING THE PERIODIC TABLE


Today’s periodic table (cont.)


A

group

is a column on the periodic table.


Elements in the same group have similar chemical
properties and react with other elements in similar
ways.

LESSON 1: USING THE PERIODIC TABLE


Today’s periodic table (cont.)


The rows on the periodic table are called
periods
.






The atomic number of each element increases by
one as you read from left to right across each
period.

LESSON 1: USING THE PERIODIC TABLE


Today’s periodic table


Metals are on the left side and in the middle of the
periodic table.


With the exception of hydrogen, nonmetals are
located on the right side of the periodic table.


Between the metals and the nonmetals on the
periodic table are the metalloids.

LESSON 1: USING THE PERIODIC TABLE


How scientists use the periodic table


Even today, new elements are created in
laboratories, named, and added to the present
-
day
periodic table.

LESSON 1: USING THE PERIODIC TABLE


How scientists use the periodic table (cont.)


Scientists can use the periodic table to predict the
properties of new elements they create.


The periodic table contains more than 100
elements, each with its unique properties that
differ from the properties of other elements.


LESSON 1: USING THE PERIODIC TABLE


Summary


On the periodic table, elements are arranged according to
increasing atomic numbers and similar properties.


A column of the periodic table is called a group. Elements in
the same group have similar properties.


A row of the periodic table is called a period. Properties of
elements repeat in the same pattern from left to right
across each period.



LESSON 2: METALS


Key Concepts



What elements are metals?


What are the properties of metals?


LESSON 2: METALS


What is a metal?


More than three
-
quarters of the elements on the
periodic table are metals.


With the exception of hydrogen, all of the elements
in groups 1
-
12
on the periodic table are metals.


Some of the elements in groups 13
-
15 are metals.


To be a metal, an element must have certain
properties.

LESSON 2: METALS


What is a metal? (cont.)


A
metal

is an element that is generally shiny. It is
easily pulled into wires or hammered into thin
sheets. A metal is a good conductor of electricity
and thermal energy.


Luster

describes the ability of a metal to reflect
light.


Ductility

is the ability to be pulled into thin wires
.

LESSON 2: METALS


What is a metal? (cont.)


Malleability

is the ability of a substance to be
hammered or rolled into sheets.


Gold is so malleable that it can be hammered into
thin sheets.


In general the density, strength, boiling point, and
melting point of a metal are greater than those of
other elements.

LESSON 2: METALS


Group 1: Alkali Metals


The elements in group 1 are called
alkali metals
.


The alkali metals include lithium, sodium,
potassium, rubidium, cesium, and francium.


Alkali metals react quickly with other elements,
such as oxygen and in nature, occur only in
compounds.


Alkali metals react violently


with water. They are also soft


enough to be cut with a knife.

LESSON 2: METALS


Group 2: Alkaline Earth Metals


The elements in group 2 on the periodic table are
called
alkaline earth metals
.


The alkaline earth metals are beryllium, magnesium,
calcium, strontium, barium, and radium.


Pure alkaline earth


metals do not occur


naturally but instead


combine with other


elements and form


compounds.

LESSON 2: METALS


Groups 3
-
12: Transition Elements


The elements in groups 3
-
12 are called
transition
elements
.


T
ransition elements are in a block at the center and
two rows at the bottom of the periodic table.


Many colorful materials contain small amounts of
transition elements.


LESSON 2: METALS


Groups 3
-
12: Transition Elements (cont.)


All transition elements are metals with higher melting
points, greater strength, and higher densities than the
alkali metals and the alkaline earth metals.


Because of their high densities, strength, and
resistance to corrosion, transition elements make good
building materials.


Two rows of transition elements

the lanthanide and
actinide series

were removed from the main part of
the table so that periods 6 and 7 were not longer than
the other periods.

LESSON 2: METALS


Patterns in properties of metals


Metallic properties include luster, malleability, and
electrical conductivity.


LESSON 2: METALS


Summary


Properties of metals include conductivity, luster,
malleability, and ductility.


Alkali metals and alkaline earth metals react easily
with other elements. These metals make up groups
1 and 2 on the periodic table.


Transition elements make up groups 3
-
12 and the
lanthanide and actinide series on the periodic
table.

LESSON 3: METALS AND METALLOIDS


Key Concepts


Where are nonmetals and metalloids on the
periodic table?


What are the properties of nonmetals and
metalloids?

LESSON 3: METALS AND METALLOIDS


The elements of life


More than 96 percent of
the mass of the human
body comes from four
nonmetals

oxygen,
carbon, hydrogen, and
nitrogen.


LESSON 3: METALS AND METALLOIDS


The elements of life (cont.)


Nonmetals

are elements that have no metallic
properties.


The four elements that make up most of the human
body, along with phosphorus and sulfur, are the six
elements in proteins, fats, nucleic acids, and other
large molecules in your body and in all other living
things.

LESSON 3: METALS AND METALLOIDS


How are nonmetals different from metals?


Nonmetals have properties that are different from
those of metals.


Many nonmetals are gases at room temperature
and those that are solid at room temperature have
a dull surface, which means they have no luster.


Because nonmetals are poor conductors of
electricity and thermal energy, they are good
insulators.


LESSON 3: METALS AND METALLOIDS


Phosphorus and carbon are dull, brittle solids that
do not conduct thermal energy or electricity.

LESSON 3: METALS AND METALLOIDS


How are nonmetals different from metals?
(cont.)


An element in group 17 of the periodic table is
galled a
halogen
.


The term
halogen
refers to an element that can
react with a metal and form a salt.

LESSON 3: METALS AND METALLOIDS


How are nonmetals different from metals? (cont.)


Halogens react readily with other elements and form
compounds.


Halogens can only occur naturally in compounds.


In general, halogens are less reactive as you move
down the group.


The elements in group 18 are known as the
noble
gases
.

LESSON 3: METALS AND METALLOIDS


How are nonmetals different from metals? (cont.)


Unlike the halogens, the only way elements in this
group react with other elements is under special
conditions in a laboratory.


Of all the elements, hydrogen has the smallest atomic
mass and is the most common element in the universe.


Hydrogen is most often classified as a nonmetal
because it has many properties like those of
nonmetals.


However, hydrogen also has some properties similar to
those of the group 1 alkali metals.


Under conditions on Earth, hydrogen usually behaves
as a nonmetal.

LESSON 3: METALS AND METALLOIDS


Metalloids


Between the metals and the nonmetals on the
periodic table are elements known as metalloids.

LESSON 3: METALS AND METALLOIDS


Metalloids (cont.)


A
metalloid

is an element that has physical and
chemical properties of both metals and nonmetals.


The elements boron, silicon, germanium, arsenic,
antimony, tellurium, polonium, and astatine are
metalloids.


Silicon is the most abundant metalloid in the
universe.

LESSON 3: METALS AND METALLOIDS


Metalloids (cont.)


A property of metalloids is the ability to act as a
semiconductor.


A
semiconductor

conducts electricity at high
temperatures, but not at low temperatures.


Silicon is used in making semiconductor devices for
computers and other electronic products.


LESSON 3: METALS AND METALLOIDS


Metals, nonmetals, and metalloids


An element’s position on the periodic table tells you
a lot about the element.


Understanding the properties of elements can help
you decide which element to use in a given
situation.

LESSON 3: METALS AND METALLOIDS


Summary


A nonmetal is an element that has no metallic
properties. Solid nonmetals are dull and brittle and
do not conduct thermal energy or electricity.


Halogens and noble gases are nonmetals. These
elements are found in group 17 and group 18 of
the periodic table.


Metalloids have some metallic properties and some
nonmetallic properties. The most important use of
metalloids is as semiconductors.

CHAPTER WRAP
-
UP


Lesson 1: Using the Periodic Table


Elements are organized on the periodic table by
increasing atomic number and similar properties.


Elements in the same group, or column, of the
periodic table have similar properties.


Elements’ properties change across a period, which
is a row of the periodic table.


Each element key on the periodic table

provides the name, symbol, atomic number, and
atomic mass for an element.


CHAPTER WRAP
-
UP


Lesson 2: Metals


Metals are located on the left and middle parts of
the periodic table.


Metals are elements that have ductility,
malleability, luster, and conductivity.


The alkali metals are in group 1 of the periodic
table, and the alkaline earth metals are in group 2.


Transition elements are metals in groups 3
-
12 of
the periodic table, as well as the lanthanide and
actinide series.

CHAPTER WRAP
-
UP


Lesson 3: Nonmetals


and Metalloids


Nonmetals are on the


right
side of the periodic table, and metalloids are
located between metals and nonmetals.


Nonmetals are elements that have no metallic
properties. Solid nonmetals are dull in appearance,
brittle, and do not conduct electricity. Metalloids are
elements that have properties of both metals and
nonmetals.


Some metalloids are semiconductors.


Elements in group 17 are called halogens, and
elements in group 18 are noble gases.